Tapered roller bearing

Abstract

A tapered roller bearing includes: an inner ring; an outer ring; a plurality of tapered rollers having a roller large end face that is a convex curved surface; and an annular cage that holds the tapered rollers at intervals along a circumferential direction. The inner ring includes a large rib portion having a rib surface that is a concave curved surface and that contacts the roller large end face. Inequalities represented by R>Ri>Rr are satisfied, where Rr is a curvature radius of the roller large end face, Ri is a curvature radius of the rib surface in a longitudinal cross section of the inner ring, and R is a distance from a cone center to a center of a contact ellipse obtained by contact between the roller large end face and the rib surface.

What is claimed is: 
     
       1. A tapered roller bearing comprising:
 an inner ring having a tapered inner ring raceway surface; 
 an outer ring having a tapered outer ring raceway surface; 
 a plurality of tapered rollers that is able to roll on the inner ring raceway surface and the outer ring raceway surface, the tapered rollers each having a roller large end face that is a convex curved surface; and 
 an annular cage that holds the tapered rollers at intervals along a circumferential direction, wherein 
 the inner ring includes a large rib portion having, on a large diameter side thereof, a rib surface that is a concave curved surface and that contacts the roller large end face, and 
 inequalities represented by R>Ri>Rr are satisfied, where Rr is a curvature radius of the roller large end face, Ri is a curvature radius of the rib surface in a longitudinal cross section of the inner ring, and R is a curvature radius of the rib surface when the rib surface is viewed from a radially outer side in a direction orthogonal to a virtual straight line connecting a cone center to a center of a contact ellipse obtained by contact between the roller large end face and the rib surface. 
 
     
     
       2. A tapered roller bearing comprising:
 an inner ring having a tapered inner ring raceway surface; 
 an outer ring having a tapered outer ring raceway surface; 
 a plurality of tapered rollers that is able to roll on the inner ring raceway surface and the outer ring raceway surface, the tapered rollers each having a roller large end face that is a convex curved surface; and 
 an annular cage that holds the tapered rollers at intervals along a circumferential direction, wherein 
 the inner ring includes a large rib portion having, on a large diameter side thereof, a rib surface that is a concave curved surface and that contacts the roller large end face, and 
 a contact ellipse obtained by contact between the roller large end face of the tapered roller bearing and the rib surface of the large rib portion is shaped like an ellipse that is smaller in a circumferential direction of the inner ring than a direction orthogonal to the circumferential direction.